Process of treating wood for buoyant articles and product thereof.



UNITED STATES PATENT orrrcn.

ROBERT ATHELSTAN MARK, 0F NORFOLK, VIRGINIA, ASSIG-NOIB. T0 AMERICAN WOOD ENCYSTING 00., INCORPORATED, 0F NORFOLK, VIRGINIA, A CORPORATION OF VIRGINIA.

PROCESS OF TREATING WOOD FOR BUOYANT ARTICLES AND PRODUCT THEREOF.

No Drawing.

To all whom it may concern:

Be it known that I, ROBERT ATHELSTA'N IVIARR, citizen of the United States, residing at Ghent, Norfolk, in the State of Virginia, have invented certain new and useful Improvements in Processes of Treating Wood for Buoyant Articlesand Products Thereof, of which the following is a specification.

The present invention relates to the treatment of woods of low specific gravity, to render them. particularly suitable for use in making various buoyant articles, such as life preservers, fenders, floats, buoys and the like.

It is a well known fact that certain varieties of wood, particularly balsa and ceiba woods, are very light, that is they possess a very low specific gravity (about .25) and it has been proposed to use these Woods in place of cork in life belts and similar devices, but it has been found that these woods are not entirely suited for the purposes mentioned, for the reasons, first, that they readily absorb and take up large quantities of water, which greatly decreases their buoyancy and secondly these varieties of 'wood are very susceptible to decay and insect attack, such as attacks by teredo and other wood destroying organisms. These objectionable properties render the wood in its natural condition, unsuited for use in life preservers and in substantially all buoyant articles, and accordingly most of the suggestions heretofore made for so employing these varieties of Woodhave not been entirely successful.

In my prior U. S. patents, dated April 16, 1912, Nos. 1,023,745 and 1,023,784., I have described two processes in which different kinds of wood can be impregnated by various materials including melted paraflin, which processes will prevent the absorption of water by the woods, and which will also prevent, decay, and the ravages of various marine insects and other similar Wood destroying agencies.

In my copending application Serial No. 747,169, filed Feb, 8, 1913, I have described a process of preserving wood, by the treatment of wood with a bath containing paralfin, naphthalene and diatomaceous earth, which process, I have now found, to be particularly suitable for the application to the Specification of Letters Patent. Patented De 22, 1914 Application filed January 13, 1914. Serial No. 811,909.

varieties of wood above referred to, and I have also found that certain'modifications of this process are also capable of produclng excellent results in the treatment of woods of these stated varieties and similar kinds of wood, suitable for use in the production of buoyant articles, as well as for structural purposes.

In carrying out my present invention, wood in pieces of suitable size and shape for use in making the life preservers or other articles above referred to is subjected to the action of a bath comprising paraifin, naphthalene and diatomaceous earth, to which bath a small amount of rosin and of Paris green may or may not be added depending upon whether or not the production of certam properties referred to later on is desired. This bath will preferably be maintained at a temperature somewhat above the boiling point of water, a temperature of 250 F. being suitable, during the action of which bath, the moisture content of the wood is largely or entirely driven out, and more or less,of the bath is absorbed by the wood. The temperature of the bath may be lowered more or less, depending upon the amount of impregnation or encysting of the wood which is desired. For the production of blocks of Wood for use in life preservers, it is ordinarily not necessary or desirable to give a heavy impregnation, for the reason that it is'desirable to produce a finished product, having as low a specific gravity as possible, in order to have a high buoyant effect. In order to produce the low impregnation, I preferably do not allow the temperature of the bath to fall more than a few degrees, say from 2509 F. at the.

beginning of the operation, down to 180 or 200 F., atvwhich point the wood is preferably removed from the bath, and allowed to further cool to ordinary temperature.

Instead of allowing the temperature of the entire bath to fall, after the wooden articles have been immersed in the hot bath for a short time, at a temperature of 250 F.

(more or less) I may remove said articles from the bath, and immerse the two ends of the same (first one end and then the other) in a bath of similar composition, or another bath, maintained at a temperature of 180 F. (more or less). The second bath agencies.

obviously may consist of the same materials, and in the same proportions, as I used in the first bath, the temperature of said bath being lower, or if desired, the second bath may consist of the same materials, and 1n different proportions from the first bath, or if desired, the second bath may consist of difi'erent materials from those employed in the first bath; Any liquid, or material which is-liquid at the temperature desired for the second bath, say 180 F., which is not injurious to the wood, or to the ingredients of the first bath, may be employed for this second bath. I

The time of immersion and cooling may vary more or less depending on the size of the wooden pieces, the amount of 1mpregna-.

tion desired, moisture content of the wood, and other factors, but I have found that for blocks of balsa wood of two inches square, and four inches long, a hot bath for five minutesand then cooling to 180 F., during two minutes, has been found to give eXcellent results.

The impregnation of the surface portions of the wood is in this manner made quite complete, while the interior portions of the wood are not saturated with the impregnating material; but a small amount of the material will be carried, by means of the large ducts existing in these varieties of wood, practically throughout the'body of, the material, whereby the paraflin, naphthalene and diatomaceous ,earth, are caused to be thoroughly disseminated in very small amounts, throughout the entire body of the wood, while the small air spaces throughout thebody of the wood are not filled with the impregnating material.

In this way I can produce blocks having very lowspecific gravities which will be thoroughly and completely waterproofed,

and preserved against rot, and attack of marine insects and similar wood-destroying As a modified mode of procedure I can incase the blocks of wood, in the duck, can vas or other fabric forming the body of the life belt or similar structure, and then treat the finished article by the process of im pregnation, which not only preserves the wood, but also preserves the fabric against the destructive agencies such as dry rot and the like, and makes it waterproof.

In making certain other kinds of buoyant articles, it is not desired to produce such a high degree of buoyancy, instances of this being buoys for anchoring boats and the like, and in the treatment of articles of this character, I find that a heavy impregnation of the article with the preservative specified is a material advantage, since these articles are likely to be deeply chipped by the action of boats striking the same, and a complete impregnation or substantial saturation of to 275 260 being preferred, then allow the temperature to drop slowly, while the wood is immersed in the liquid, to a temperature down to near the solidifying point of the treating bath.

For treating wood for the construction of boats, particularly life boats and the like, I subject the material to a heavy impregnation, which gives considerably more strength to the material, than would be produced by a light impregnation.

In carrying out the impregnation process in all the modifications the material is immersed and held under the surface of the bath. I desire to call attention to. the fact that the wood when so treated, may be coated, if so desired, over all or a part of its surface with paint, either for ornamentation, or marking purposes. In using ordinary paint, it is coat of shellac.

' Ifjdesired I may add to the impregnating bath any suitable oil-soluble dye, which will be carried into the wood, wherever the preservative is carried. f

The bath used in impregnating the material may consist of the materials in the following proportions by weight, although the invention is not limited thereto, and the pro portions may be materially altered without departing from the spirit of the invention; paraflin parts, naphthalenefi to 7 parts, diatomaceous earth 2 to 7 parts,- (to which may be added if desired, or Paris green 1 part, or bothjql,

The naphthalene employed in this process preferable to first apply a to 5 parts, i

acts as a conveying agent, for carrying the The use of rosin is, as above stated, son1ewhat optional. This material hardens the wood to a considerable extent, also makes the wood tougher, and gives a somewhat adhesive condition to the surface of the wood, thereby making the treated material more easy to cling to. i v

The wood for ring buoys may be made in the form of rings, which may be built up herein disclosed is described and claimed.

(composed of three or more layers, united by a suitable waterproof glue) if desired,

and tl1ese..may,.be covered by duck or the like, before impregnatiom if desired. Also I may treat the wood in the form of large pieces, logs or the like, and afterward, if

small pieces are needed I may cut this todissemination of the preservative throughout the body of the wood, is aided by osmosis.

The treatment of wood with a mixture including paraflin, rosin and diatomaceous earth, with or without Paris green, and a dye soluble in the bath, is claimed'inmy copending application Serial No. 811,910, filed Jan. 13, 1914. The treatment of fabrics and other textile materials, by the methods in my copending applications Nos. 811,911

and $11,912, both filed Jan. 13, 1914.

lVhat I claim is v 1. A process of treating woods of low specific gravities in their natural condition, which comprises impregnating said woods with a hydrocarbon material containing a finely dividedsolid material.

'2. A process of treating woods of low specific gravities, which comprises impregnating said woods in their natural condition, with hydrocarbon material containing a finely divided solid material.

A process of treating woods of low specific gravity, which comprises immersing steps of placing said wood in a permeable envelop, and thereaftersubjecting the same to a heated bath of paraffin, diatomaceous earth and a conveying agent.

6. A process of treating wood of low specific gravity, which comprises immersing the same in a bath containing paraflin, naphthalene and diatomaceous earth, at a temperature materially above the boiling point of water, then treating the same with a bath at a temperature lower than that employed in said first treatment.

7. A prooess'of treating wood, which comprises treating the same with a bath containing diatomaceous earth, a vehicle insoluble in water and a material capable of increasingthe rate of penetration of said vehicle.

8. A process of treating balsa, ceiba and similar varieties of wood which comprises treating the same with a bath comprising pa ratlin, naphthaleneand diatomaceous earth, at a high temperature, then with a bath composed of materials not injurious to the wood, or to the ingredients of said first bath, said second bath being at a lower temperature, until the desired impregnation is secured.

9. A process of treating balsa, ceiba, and similar varieties of wood which comprises treating the same with a bath comprising parafiin, naphthalene, rosin and di'atomaceous earth, at a high temperature, then with a bath capable of increasing the amount of absorption of said first bath, said second bath being at a lower temperature,untilthe desired impregnation is secured. 1

10. A process of treating balsa, ceiba, and similar varieties of wood, which comprises treating the same with a bath comprising paraffin, naphthalene, rosin, Paris green, and diatomaceous earth, at a high temperature, then with abath containing at least some of the ingredients of said first bath, said second bath being at a lower temperature, until the desired impregnation is secured.

11. A process of treating balsa, ceiba, and similar varieties of wood which comprises treating the same while incased in a fabric cover with a bath comprising 'paraflin, naphthalene and diatomaceous earth, at a high temperature, then with a bath containing parafiinat a lower temperature, until the desired impregnation is secured.

12'. A process of treating balsa, ceiba, and other similar varieties of wood, which comprises subjecting the same to the action of a bath containing paraffin, naphthalene, diatomaceous earth and rosin. I

13. A process of treating-wood of those varieties having a relatively low specific gravity, same in a bath comprising paraffin, naphthalene, rosin, Paris green, and diatomaceous earth.

14.. An article of manufacture comprising a wood of relatively low specific gravity impregnated with a preservative including diatomaceous earth, a vehicle comprising parafiin and a somewhat volatile, aromatic hydrocarbon.

15. An article ofmanufacture comprising a wood of relatively low specific gravity,

impregnated with apreservative including balsa and ceiba which comprises immersing the diatomaceous earth, and a vehicle comprising paraflin and naphthalene.

16. An article of manufacture comprising a wood of relatively low specific gravity,

impregnated with a preservative including abalsa wood, impregnated with a preservative including diatomaceous earth, and a vehicle comprising paraffin.

19.- An article of manufacture comprising wood of relatively low specific gravity, impregnated with a preservative material including an insoluble finely divided solid material, having a hardness greater than that of the material of which the biting parts of marine wood-destroying worms is composed,

and an insoluble hydrocarbon carrier which 1 melts at a temperature below the boiling point of water, and which is solid at ordinary temperatures, and a material capable of increasing the rate of penetration of said preservative materiaL,

20. An article of manufacture comprising wood of relatively low specific gravity, impregnated with a preservative material including an insoluble finely divided solid material, having a hardness greater than that of the material of which the biting parts of marine wood-destroying worms is composed,

' and an insoluble hydrocarbon carrier which melts at a temperature below the boiling point of water, and which is solid at ordinary temperatures, said Wood being coated with a material including an insoluble poisonous compound.

In testimony whereof I have afiixed my signature in presence of two witnesses.

ROBERT ATHELSTAN MARR.

Witnesses:

J AivEY Horn MARK, A; B. FQSTER. 

